If you are planning to use chemical controls, you should remove the dead mare’s tail ideally in the winter months or early spring.
Do not spray too early in the season, but instead wait until the horsetail is approximately four to six inches tall.
Spray using a herbicide onto the weed and ensure the plant is fully covered with a fine or medium spray.
Mare’s tail usually takes one to two weeks to turn brown but will take longer to disappear and die.
The longer you wait the more likely you are to see better results.
Once the mare’s tail is black and dead, it can be raked and cleared away, which is due to its ability to regrow it from very tiny root particles.
Often repeat applications are needed to ensure horsetail disappears permanently.